Roomlight handling radiographic element including an x-ray sensitive layer overcoated with a dye desensitized silver halide emulsion



Feb. 22, 1966 C. DOSTES ET AL ROOMLIGHT HANDLING RADIOGRAPHIG ELEMENTINCLUDING AN X-RAY SENSITIVE LAYER OVERCOATED WITH A DYE DESENSITIZEDSILVER HALIDE EMULSION Filed Jan. 19, 1961 LIGHT-BLOCKING SILVER HAL/DEEMULSION LAYER X-RAY SENSITIVE LAYER SUPPORT 5A LIGHT SEALING BACKINGLAYER LIGHT-BLOCKING SILVER HAL/DE EMULSION LAYER X-RAY SENSITIVE LAYER8U P PORT -RAY SENSITIVE LAYER I LI6HT BLOCKING SILVER HAL/DE EMULSIONLAYER Claude Dosies MauriceEPfaff' INVENTORS %MM ZQWZ ATTORNEYfi UnitedStates Patent 3,237,008 ROOMLIGHT HANDLING RADIOGRAPHIC ELE- MENTINCLUDING AN X-RAY SENSITIVE LAYER OVERCOATED WITH A DYE DESENSI- TIZEDSILVER HALIDE EMULSIGN Claude Dostes, Joinville-le-Pont, Seine, andMaurice E. Pfatf, Eaubonne, Seine-et-Oise, France, assignors to EastmanKodak Company, Rochester, N .Y., a corporation of New Jersey Filed Jan.19, 1961, Ser. No. 83,709 5 Claims. (Cl. 25065) This invention relatesto photographic elements which have the light-sensitive layer or layersthereof protected from exposure to visible light. More particularly itrelates to elements which are useful in obtaining X-ray photographs orradiograms. Still more particularly it relates to X-ray films which canbe safely handled and processed under conditions of ordinary room-lightillumination without exposure of the photosensitive layers thereof.

There have been various methods proposed in the art for protecting thelight-sensitive layer or layers of photographic elements used inobtaining X-ray photographs. Certain of these photographic elements havebeen provided with an opaque protecting medium which is removed afterexposure in a special processing bath. Such protective layers have notbeen entirely satisfactory because the layers are diflicult to removeafter exposure to X-rays and the light-blocking material is not alwaysuniformly distributed throughout the medium. Other radiographic elementshave been prepared using protective outer-layers, comprising a coatingof chrome-yellow, Venetian red, and the like which forms a readilyremovable opaque protecting medium. This coating allows handling of theelement in ordinary room light but is washed off prior to development sothat development must of necessity be carried out in a darkroom. Withany of the prior proposals for protecting the light-sensitive layerusing an outer-protective opaque layer, there has also been thedifficulty that these protective layers do not cover the edges of thefilm, and accordingly, light enters the film through these edges toproduce edge-fog in the light-sensitive emulsion layer. To overcome thisdifficulty, it has been proposed to optically seal the edges of the filmby applying a black colloid edge-coating or a sealing strip of opaquepaper or fabric. It is apparent that the prior art has been unable todeduce a method for preparing a truly satisfactory roomlight handlingphotographic element. To meet the requirements of such an element, itshould be stable to visible light exposure but have substantiallyunchanged sensitivity to X-ray radiation. The element should also bestable against edge-fog without requiring special treatment or expensiveextra handling of separate film sheets to employ special opticalsealers, light-blocking cassettes, etc. The roomlight handling elementsshould also be adapted to processing in conventional processingsolutions without loss of optimum quality in the final result. It willbe apparent from a reading of the present specification and claims thatwe have found, quite unexpectedly, a way to prepare roomlight handlingphotographic elements which meet each of the above requirements while atthe same time allowing the operator to watch the complete developmentprocess under ordinary room light.

It is therefore an object of the present invention to provide aphotographic element for X-rays which can be handled under conditions ofordinary roomlight illumination. A further object is to provideroomlight handling radiographic elements which are stable against edgefog. A still further object is to provide an element which can beprocessed in room light using conventional processing "ice solutions.Another object is to provide roomlight handling radiographic elementswhich have light-blocking outer protective layers which permitobservation of image development in ordinary room light. Another andstill further object is to provide such elements wherein thelight-absorbing materials are readily removed in conventional fixingbaths. Other objects will appear hereinafter.

According to the present invention the roomlight handling radiographicelement carries an outer emulsion layer which is a light-blocking layerfor the inner-most light sensitive, X-ray sensitive emulsion layer. Theobjects of the invention are accomplished by incorporating in each ofthe emulsion layers of the roomlight handling photographic element, acombination of a nitrogen-containing heterocyclic silver halidedesensitizing compound and a yellow dye which absorbs a substantialportion of the visible radiation to which the silver halide is sensitive(i.e., radiation between about 350 and 500 mu). According to the presentinvention, the desensitizing compounds should be capable of stronglydepressing the light sensitivity of the silver halide withoutappreciably alfecting the X-ray sensitivity. The desensitized .silverhalide grains should be readily removed from the layers of theradiographic elements in conventional processing baths. The dyes used ineach layer should also be readily removed or decolorized in conventionalprocessing solutions. In the outermost light-blocking layer, thestrongly desensitized silver halide should be readily removed inconventional processing solutions but not until development of theinnermost layer has occurred. After roomlight processing, both thesilver halide and the incorporated dye should be removed from .alllayers or decolorized leaving a clearly visible radiographic image.

By reference to the accompanying drawing, there can be seen the mannerin which the roomlight handling radiographic elements of our inventioncan be prepared. FIG. 1 shows a sectional view of a photographic elementhaving a light-sealing backing layer, whereas FIG. 2 shows an elementwhich has an X-ray sensitive layer and a lightblocking layer on eachside of the single support.

The nitrogen-containing heterocyclic silver halide desensitizingcompounds which are useful in the practice of our invention canadvantageously be represented by the following structural formulas:

1 0 NO /S 2-methyl-5-nitrobenz0thiazole metho-p-toluenesulfonatel-methyl-S-nitroquinolinium methosulfate 4-nitro 6-ch1orobenzotriazole--C2Ha 6-ethoxy-2- (m-nitrostyryl) quinolinium ethylethosulfate3,7-diamlno-5-pheny1-phenazinium chloride OzN 5-nitrobenzimidazoleAdditionaluseful nitrogen-containing hererocycles representative of theabove classes comprise the following:

2- (o-nitrostyryl) -3 -ethylbenzothiazolium iodide, 2-.(o,p-dinitrostyr-yl) -benzotl1iazole, 6-nitro-benzo-1,2,3-triazole,4-chloro-benzo-1,2,3-triazole,

OCHB CH=CH 01- (2) 2(4'-methoxystyryl) quinoline hydrochlorideOH=CHO-CH3 c1- H (3) The condensation product from two molecularproportions of quinaldine methylsulfate and one molecular proportion of4:4'-diphenyl dialdehyde in pyridine: The yellow-colored product of theprobable formula:

CH=CH CH=CH N1 Q N: 5

CH3 H3 (4) The condensation product from two molecular proportions ofquinaldine dimethylsulfate and one molecular proportion of azoxybenzalaniline in pyridine: The yellowcolored product of the probableformula:

S-chloro-benzo-l,2,3-triazole, 2-methyl-fi-nitrobenzothiazolemetho-p-toluene sulfonate 2- (p-nitrostyryl) -quinolinemetho-p-toluenesulfonate,

4- (p-nitrostyryl) -quinoline methoiodide, 1-ethyl-7-nitro-quinoliniumethylsulfate, 1,3-diamino-S-methylphenazinium chloride,1,3-diamino-S-benZyIphenaZinium chloride,3,7-diamino-5fi-hydroxy-ethylphenazium chloride, S-chlorobenzimidazole,

2-methyl-5-chlorobenzimidazole, Z-mercaptobenzimidazole,2-mercapto-6-chlorobenzimidazole,' 4

The desensitizing compounds of the above type which can beadvantageously employed in practicing our invention have been describedin one or more of the following representative US. Patents: 2,400,872,May 28, 1946; 2,541,472, February 13, 1951; 2,939,789, June 7, 1960;2,915,395, December 1, 1959; and 2,066,099, December 29, 1936.

The visible-light absorbing dyes which are used in combination with thedesensitizing compounds of this invention in the silver halide emulsionlayers should advantageously be dyes which are stable in a colloidcarrier and should advantageously be nondilfusing. To be suitable, theyshould be readily removable in the customary processing baths or bedecolorized entirely by the con- (5) The styryl-containing condensationproduct from quinaldine-methylsulfate and piperonal:

(6) The styryl-containing condensation product fromquinaldine-methylsulfate and veratric aldehyde:

CH3 S 04- CH:OH OCH3 CHaSOF (7) The styryl-containing condensationproduct from quinaldine-methylsulfate and anisaldehyde:

yon=orro CH3 (8) The styryl-containing condensation product from 752-'methyl-3-methylbenzthiazole-methylsulfate with ,p-ami- CHaSOrno-benzaldehyde and reacted with undecoylchloride in the presence ofpyridine and having the probable formula:

H2C S 10) 4 (phenylazo)-5-pyrazolone-3-carboxylic acid calcium salthaving the formula:

prepared according to the disclosure of US. Patent 2,503,- 717, issuedApril 11, 1950.

11) 4,4 methenyl-bis-(1-naphthyl-3-methyl-pyrazolone-) of the formula:

u as

(12) 3 carboxy-1-(1'-sulfophenyl)-4-(4-sulfophenylazo -5-pyrazolone,disodium salt:

(I O O H i O=CN SOsNa Other S-pyrazolone dyes of the type suitable foruse in the present invention comprise bis[1-(p-sulfophenyl)-3- methyl5-pyrazolone-(4)]-methinoxonol; bis[1-(p-sulfophenyl) 3methyl-5-pyrazolone-(4) ]trimethinoxonol; bis [3methyl-1-p-su1fophenyl-S-pyrazolone-(4)-]pentamethinoxonol; and othersas disclosed in US. Patent 2,852,386, issued September 16, 1958.

The yellow-colored dyes of Formulas 1 and 2 can be prepared by heatingstyryl quinoline containing a reactive methyl group with a substitutedaromatic aldehyde in the presence of anhydrous zinc chloride in a sealedtube at 100 C. for several hours. After the heat treatment, the productis treated with hydrochloric acid and hot water, filtered and madealkaline with-ammonia. The precipitated styryl derivative of the basecan then be recrystallized and converted to the salt by the addition ofacid.

The light-absorbing compounds of the above type which can beadvantageously employed in practicing our invention have been describedherein or are described in one or more of the following representativepatents: US. 2,274,- 782, March 3, 1942; 2,503,717, April 11, 1950;2,058,725,

6 October 27, 1936; 2,186,731, January 9, 1940; 1,845,404, February 16,1932; and British 399,387, October 5, 1933.

According to our invention, we incorporate in each silver halideemulsion layer of the roomlight handling element one or more of thedesensitizing compoundswith one or more visible light-absorbingcompounds, each of which are represented hereinabove. The desensitizingcompounds and the visible light-absorbing materials can be contained incombination in various concentrations in the layers of the roomlighthandling radiographic elements.

Ordinarily in the innermost layer which is X-ray sensitive and alsolight sensitive, we employ a desensitizing compound in the order of fromabout 3.0 mg. to about 300 mg. per mole of silver halide. Thelight-absorbing dye of the styryl-nucleus-containing type is added tothe emulsion in a concentration in the order of from about 0.5 to about5.0 grams per mole of silver halide and dyes of the S-pyrazolone typeare added to the emulsion in the range from about 10 to about grams permole of silver halide.

The outer-light-blocking protective layer normally comprises a silverhalide emulsion layer more strongly desensitized than is the innermostlight-sensitive layer. In the outermost layer, we normally employ anexcess of desen sitizing compound, this can be in the order of fromabout 20 mg. to 5.0 grams per mole of silver halide or more depending tosome extent upon the desensitizing compound employed. The visiblelight-absorbing dye is added in combination with the desensitizingcompound in the emulsion in an amount from about 0.5 to about 5.0 gramsper mole of silver halide for styryl-nucleus-containing dyes and fromabout 10 to 100 grams per mole of silver halide for the 5-pyrazolonedyes. In the outer-light-blocking emulsion layer a suitableconcentration of silver per square foot can vary from about 100 to about900 mg. of silver per square foot.

The outer-light protecting emulsion layer can comprise a silver halideemulsion which forms latent images predominantly inside the silverhalide crystal, such as those described in Davey and Knott, U.S. Patent2,592,250, issued April 8, 1952. Where emulsions of this type are usedaccording to the invention, desensitizing compounds of the type hereindescribed are incorporated in an amount in the range from about 25 mg.to about 250 mgv per mole of silver halide. In such emulsion layers thelight-absorbing dyes are contained in combination with desensitizingcompounds in the range as indicated above for outer-lightblockinglayers.

Silver halide emulsions which form latent images predominantly insidethe silver halide crystal are also referred to as internal imageemulsions and have been described in the co-pending application ofLuckey et al., US. patent application Serial No. 786,225, filed January12, 1959, now US. Patent 2,996,382, issued on August 15, 1961. Theinternal image emulsions which are useful according to our inventionhave a reduced surface sensitivity. Such internal image emulsions, whenmeasured according to normal photographic techniques by coating a testportion of the emulsion ion a transparent support, exposing to alight-intensity scale having a fixed time between 0.01 and 1 second,bleaching 5 minutes in a 0.3 percent p0- tassium ferricyanide solutionat 65 F., and developing for about 5 minutes at 65 F. in developer Bbelow, has a sensitivity, measured at a density of 0.1 above fog,appreciably greater (e.g., at least 1.4 log E greater) than thesensitivity of an identical test portion which has been exposed in thesame way and developed for 6 minutes at 68 F. in developer A below.

The developer compositions which are used in defining an internal imageemulsion by comparison with a conventional surface image emulsiondeveloper, compositions A and B are given hereinafter. Developer A isthe usual type of surface image developer and developer B is an internaldeveloper having high silver halide solvent activity.

The following developer compositions are used in the method ofdetermining relative internal sensitivity of preferred emulsions:

(A): Grams N-methyl-p-aminophenol sulfate 0.31 Sodium sulfite,desiccated 39.6 Hydroquinone 6.0 Sodium carbon-ate, desiccated 18.7Potassium bromide 0.86 Citric acid 0.68 Potassium metabisulfite 1.5Water'to make 1.0 liter.

N-methyl-p-aminophenol sulfate 2.0 Sodium sulfite, desiccated 90.0Hydroquinone 8.0 Sodium carbonate, monohydrate 52.5 Potassium bromide5.0 Sodium thiosulfate 10.0

Water to make 1.0 liter.

Suitable internal image emulsions are described in Davey and Knott, US.Patent 2,592,250, issued April 8, 1962. Other emulsions which can beused in the outermost layers of the present invention comprise, forexample, relatively insensitive silver chlorobromide and silverbromoiodide emulsions.

The methods of incorporating the desensitizing compounds and visiblelight-absorbing materials in silver halide emulsions are well known tothose skilled in the art. The desensitizing compounds can be directlydispersed in the emulsions, or they can be dissolved in Water (or inorganic solvents, such as methanol, ethanol, etc., where thewater-solubility is not sufficiently great) and added in the form oftheir solutions. While the visible light-absorbing dyes can be directlydispersed in the emulsions, it is convenient to add the same in the formof solutions in appropriate solvents. Methanol, ethanol, pyridine, andthe like have proved satisfactory for many of the dyes herein disclosed.Mixtures of solvents, e.g., pyridine diluted with methanol or acetone,can also be used. According to the invention the desensitizing compoundsand the visible light-absorbing dyes are dispersed in the finishedemulsions and should be uniformly distributed throughout the emulsions.The following procedure is satisfactory:

Stock solutions of the desensitizing compounds and visiblelight-absorbing dyes are prepared by dissolving the same in appropriatesolvents as described above. The desired amount of the stock solution ofone of the dyes (or desensitizing compounds) is slowly added to theliquid gelatino-silver halide emulsion with stirring. Stirring iscontinued until the dye is thoroughly incorporated in the emulsion. Thenthe desired amount of the stock solution of the desensitizing compound(or dye, if the desensitizing compound has been added first) is slowlyadded to the emulsion, while stirring. Stirring is continued until thesecond solution is thoroughly incorporated. The treated emulsion canthen be coated out on a suitable support, such as glass, cellulosederivative film, resin film, or paper, to suitable thicknesses andallowed to dry. Most usually the roomlight handling radiographicelements of our invention are duplicoated, i.e., coated on either sideof a ,X-ray-sensitive layer of the multilayer radiographic elementsprepared according to the invention can vary widelY, but in generalthicknesses from about 0.4 to about 1.2

mils, can be used. The thicknesses of the outer-protective layers arenot critical and can depend more upon the concentration of the lightdiflusing, e.g., silver halide, and

absorbing materials per square foot of coated surface.

The following examples will serve to illustrate further the presentinvention.

EXAMPLE 1 To a liquid coarse grain gelatino-silver bromoiodide emulsion,prepared in the usual manner, was added per mole of silver halide, 50mg. of Z-methyl-S-nitrobenzothiazole metho-p-toluenesulfonate (I) and0.5 gram of 2-(2- methoxystyryl)quinoline hydrochloride (II). Thereafterthe emulsion was coated at F. according to US. Patent 1,947,160, issuedFebruary 13, 1934, on both sides of an ordinary cellulose acetate film,and dried.

On either side of the coated support in the same manner an internalimage emulsion was coated which was prepared according to the disclosureof US. Patent 2,592,- 250, issued April 8, 1952, into which had beenadded with stirring 50 mg. of compound I and 0.5 gram of compound II permole of silver halide. The additions to the emulsion were made whileholding at 90 F. The emulsion composition was coated at 90 F. at athickness to give 600 mg. of silver halide per square foot, and dried.

The resulting film was exposed to an 80 kv. X-ray source under roomlightillumination, developed in a bath of the composition of Table 1, fixed,and washed. All of the steps for processing of the roomlight handlingradiographic element of this example were carried out under ordinaryroomlight illumination. The radiogram produced by this example was ofgood quality and did not show evidence of edge fog.

In the present invention the speed of the innermost layer canadvantageously be from about 50 to about times that of the outer-lightblocking layer when developed in a surface developer, such as developerA above.

Table 1 Water at F cc 500 N-methyl-p-aminophenolsulfate grams 2.0 Sodiumsulfite (dessicated) do 90.0 Hydroquinone do 8.0 Sodium carbonatemonohydrate do 52.5 Potassium bromide do 5.0 Water to make 1.0 liter.

EXAMPLE 2 A clean cellulose acetate film base was coated according toExample 1 with a coarse grain silver 'bromoiodide emulsion prepared inthe usual manner which had been desensitized with 43.5 mg. of4-nitro-6-chlorobenzotriazole (I) and to which was added 25 grams of3-carboxy 1- 1-sulfophenyl -4 (4"-sulfophenylazo -5-pyrazolone disodiumsalt (II) per mole of silver halide. The silver content of the coatingwas 882 mg. per square foot. As an outer-light-blocking layer afine-grain, silver bromoiodide emulsion strongly desensitized with 900mg. of compound I and containing 80 grams of compound II per mole ofsilver halide was coated over each of the light-sensitive,X-ray-sensitive layers at a thickness to give 540 mg. of silver persquare foot.

After drying the coated film was handled for 15 minutes under 40-footcandles of cool light fluorescent illumination during exposure of thefilm to an 80 kv. X-ray source and developed in a developer compositionof Example 1 to produce a radiogram of good contrast and speed andwithout the formation of edge fog.

EXAMPLE 3 -nitrostyryl)quinolinium ethylethosulfate (I) and to which wasadded 2.5 grams of 2-(4'-methoxystyryl)quinoline hydrochloride (II) permole of silver halide. The silver content of the coating was 750 mg. persquare foot.

U.S. Patent 2,592,250- was desensitized with 50 mg. of-

Table 2 Grams N-methyl-p-aminophenolsulfate 2.2 Hydroquinone 8.8 Sodiumsulfite (anhydrous) 72.0 Sodium carbonate (crystalline) 130.0 Potassiumbromide 4.0

Water to make 1.0 liter.

The exposed and developed film was then fixed in a well-known manner,washed, and dried. The resulting radiogram was of good quality andshowed substantially no edge fog.

Alternatively, the innermost and outermost coatings of theroomlight-handling radiographic elements can contain other visiblelight-absorbing dyes. For example: merocyanine dyes such as thosedescribed by Brooker et al., U.S. Patent 2,493,747, issued January 10,1950. The outer light-absorbing pigments in the outer-lightblockinglayers of our invention can also comprise lightabsorbing pigments suchas zinc oxide, lead chromate, silver chromate, the silver salt of dyesderived from thiobarbituric acid as described by A. H. Herz in U.S.Patent 2,719,088, issued September 27, 1955, and tartrazine mordantedwith polyvinyl pyrrolidone. In accordance With our invention, it ispossible to use a light filtering layer between the innermost layer andthe outermost protective layer to prevent ditfusion of additivematerials which might otherwise become introduced into the innermostX-ray sensitive layer. For example, a suitable interlayer to preventdiifusion of acid dyes was found to comprisepolyvinyl-a-rnethyl-allyl-N-quanidyl ketime and other suitable compoundsin gelatin as described in U.S. Patent 2,882,156, issued April 14, 1959.

Our invention will now be described by reference to the accompanyingdrawing. In FIG. 1 the support is coated with a light-sensitive,X-ray-sensitive layer 11 which has coated thereon a light-blockingsilver halide emulsion layer 12 which prevents the exposure of thelight-sensitive layer 11 during roomlight handling of the radiographicelement. On the back side of the element there is coated a light-sealingbacking layer 13. The backing layers suitably employed in the inventionmust be antihalation layers which dissolve smoothly in photographicdevelopers and which do not disintegrate and contaminate conventionaldeveloper solutions, such as described in U.S. Patent 2,327,828, issuedAugust 24, 1943.

In FIG. 2 of the accompanying drawing'the support 10 is coated on eachside with an X-ray-sensitive, lightsensitive layer 11 and superimposedon each of the lightsensitive layers are the light-blocking silverhalide emulsion layers 12. In roomlight handling element of the typeshown in FIG. 2, a light-sealing backing layer is not used since theOuter protective layers protect the innermost layers 11 from visiblelight exposure.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be efiected within the spirit and scope of theinvention as described hereinabove and as defined in the appendedclaims.

We claim:

1. A roomlight handling photographic element comprising a support havingcoated thereon at least one X- ray-sensitive gelatino-silver halideemulsion layer containing about 3 milligrams to 300 milligrams of anitrogen-containing heterocyclic silver halide desensitizing compoundper mole of silver halide and a yellow dye selected from the groupconsisting of styryl-nucleus containing dyes at a concentration of about,5 gram to 5 grams per mole of silver halide and 5-pyrazolone dyes at aconcentration of about 10 grams to grams per mole of silver halide, andcoated on said X-ray-sensitive layer at least one light-blockinggelatino-silver halide emulsion layer more strongly desensitized thansaid X-raysensitive layer and containing about 20 milligrams to 5 gramsof a nitrogen-containing heterocyclic silverhalide desensitizingcompound per mole of silver halide and a yellow dye selected from thegroup consisting of styrylnucleus containing dyes at a concentration ofabout .5 gram to 5 grams per .mole of silver halide and 5-pyrazolonedyes at a concentration of about 10 grams to 100 grams per mole ofsilver halide, said yellow dye being absorbent in the regions of thevisible spectrum in which said gelatino-silver halide emulsions aresensitive and suitable to transmit the rest of the visible spectrum sothat the progress of development of said X-ray-sensitive layer can beobserved in roomlight.

2. A roomlight handling photographic element comprising a support havingcoated on both sides thereof an X-ray-sensitive gelatino-silver halideemulsion layer containing about 3 milligrams to 300 milligrams per moleof silver halide of a nitrogen-containing heterocyclic silver halidedesensitizing compound and a yellow dye selected from the groupconsisting of styryl-nucleus containing dyes at a concentration of about.5 grams to 5 grams per mole of silver halide and S-pyrazolone dyes at aconcentration of about 10 grams to 100 grams per mole of silver halide,and superimposed on each of said X-ray sensitive layers a light-blockinggelatino-silver halide emulsion layer wherein the silver halide formslatent images predominantly inside the silver halide crystals morestrongly desensitized than said X-ray-sensitive layers and containingabout 25 milligrams to 250 milligrams per mole of silver halide of anitrogen-containing heterocyclic silver halide desensitizing compoundand a yellow dye selected from the group consisting of styryl-nucleuscontaining dyes at a concentration of about .5 gram to 5.0 grams permole of silver halide and 5-pyrazolone dyes at a concentration of about10 grams to 100 grams per mole of silver halide, said yellow dye beingabsorbent in the regions of the visible spectrum in which said gelatinosilver halide emulsions are sensitive and suitable to transmit the restof the visible spectrum so that the progress of development of saidX-ray-sensitive layers can be obserbed in roomlight.

3. A roomlight handling photographic element comprising a support havingcoated on both sides thereof an X-ray-sensitive gelatino-silver halideemulsion layer containing about 3 milligrams to 300 milligrams per moleof silver halide of 2-methyl-5-nitrobenzothiazolemetho-p-toluenesulfonate and about .5 gram to 5 grams per mole of silverhalide of 2(2'-methoxystyryl)quino line hydrochloride, and superimposedon each of said X- ray-sensitive layers a light'blocking gelatino-silverhalide emulsion layer that forms latent images predominantly inside thesilver halide crystals more strongly desensitized than saidX-ray-sensitive layers and containing about 20 milligrams to 5 grams permole of silver halide of 2-methyl-S-nitrobenzothiazolemetho-p-toluenesulfonate and about .5 gram to 5 grams per mole of silverhalide of 2(2'-methoxystyryl) quinoline hydrochloride, said yellow dyebeing absorbent in the regions of the visible spectrum in which saidgelatino-silver halide emulsions are sensitive and suitable to transmitthe rest of the visible spectrum so that the progress of development ofsaid X- ray-sensitive layer can be observed in roomlight,

4. A roomlight handling photographic element comprising a support havingcoated on both sides thereof an X-ray-sensitive gelatino-silver halideemulsion layer containing about 3 milligrams to 300 milligrams per moleof silver halide of 4-nitro-6-chlorobenzotriazole and about 10 grams to100 grams per mole of silver halide of 3- carboxy 1-(1-su1fophenyl)-4(4"-sulfophenylazo)-5-pyrazolone disodium salt, and having superimposedon each of said X-ray-sensitive layers a light-blocking gelatino-silverhalide layer more strongly desensitized than said X-ray-sensitive layerscontaining about 20 milligrams to 5 grams per mole of silver halide of4-nitro-6-chlorobenzotriazole and about 10 grams to 100 grams per moleof silver halide of 3-carboxy-l-(l'-sulfophenyl)-4-(4"-sulfophenylazo)-5-pyrazolone disodium salt, said yellow dye beingabsorbent in the regions of the visible spectrum in which saidgelatino-silver halide emulsions are sensitive and suitable to transmitthe rest of the visible spectrum so that the progress of development ofsaid X- ray-sensitive layer can be observed in roomlight.

5. A roomlight handling photographic element comprising a support havingcoated on both sides thereof an X-ray-sensitive gelatino-silver halideemulsion layer containing about 3 milligrams to 300 milligrams per moleof silver halide of 6-ethoXy-2-(m-nitrostyryl)quinoliniumethylethosulfate and about .5 gram to 5 grams per mole of silver halideof 2(4'-methoxystyryl)quinoline hydrochloride, and having superimposedon each of said X-raysensitive layers .a light-blocking gelatino-silverhalide emulsion layer more strongly desensitized than said X-ray-sensitive layers containing about 20 milligrams to 5 grams per moleof silver halide of 6-ethoxy-2-(mnitrostyryl)quinoliniumethylethosulfate and about .5 gram to 5 grams per mole of silver halideof 2(4'-methoxystyryl)quinoline hydrochloride, said yellow dye beingabsorbent in the regions of the visible spectrum in which saidgelatino-silver halide emulsions are sensitive and suitable to transmitthe rest of the visible spectrum so that the progress of development ofsaid X-ray-sensitive layer can be observed in roomlight.

References Cited by the Examiner UNITED STATES PATENTS 2,090,607 8/ 1937Baldsiefen 96101 2,098,442 11/1937 Troland 96108 2,503,717 4/1950 Fierkeet al. 9684 2,541,472 2/1951 Kendall et al. 96101 2,542,304 2/1951Boucher 25068 2,592,250 4/1952 Davey et al. 9694 2,725,296 11/1955Kendall 9668 2,759,822 8/ 1956 Jones et al. 9668 2,853,386 9/1958 Tong96114 2,882,156 4/1959 Minsk 96114 3,114,833 12/1963 Fine 9668 FOREIGNPATENTS 230,964 2/1911 Germany. 334,878 3/ 1921 Germany.

NORMAN G. TORCHIN, Primary Examiner.

RALPH G. NILSON, Examiner.

1. A ROOMLIGHT HANDLING PHOTOGRAPHIC ELEMENT COMPRISING A SUPPORT HAVINGCOATED THEREON AT LEAST ONE XRAY-SENSITIVE GELATINO-SILVER HALIDEEMULSION LAYER CONTAINING ABOUT 3 MILLIGRAMS TO 300 MILLIGRAMS OF ANITROGEN-CONTAINING HETEROCYCLIC SILVER HALIDE DESENTIZING COMPOUND PERMOLE OF SILVER HALIDE AND A YELLOW DYE SELECTED FROM THE GROUPCONSISTING OF STYRYL-NUCLEUS CONTAINING DYES AT A CONCENTRATION OF ABOUT.5 GRAM TO 5 GRAMS PER MOLE OF SILVER HALIDE AND5-PYRAZOLONE DYES AT ACONCENTRATION OF ABOUT 10 GRAMS TO 100 GRAMS PER MOLE OF SILVER HALIDE,AND COATED ON SAID X-RAY-SENSITIVE LAYER AT LEAST ONE LIGHT-BLOCKINGGELATINO-SILVER HALIDE EMULSION LAYER MORE STRONGLY DESENSITIZED THANSAID X-RAYSENSITIVE LAYER AND CONTAINING ABOUT 20 MILLIGRAMS TO 5 GRAMSOF A NITROGEN-CONTAINING HETEROCYCLIC SILVER HALIDE DESENSITIZINGCOMPOUND PER MOLE OF SILVER HALIDE AND A YELLOW DYE SELECTED FROM THEGROUP CONSISTING OF STYRYLNUCLEUS CONTAINING DYES AT A CONCENTRATION OFABOUT .5 GRAM TO 5 GRAMS PER MOLE OF SILVER HALIDE AND 5-PYRAZOLONE DYESAT A CONCENTRATION OF ABOUT 10 GRAMS TO 100 GRAMS PER MOLE OF SILVERHALIDE, SAID YELLOW DYE BEING ABSORBENT IN THE REGIONS OF THE VISIBLESPECTRUM IN WHICH SAID GELATINO-SILVER HALIDE EMULSIONS ARE SENSITIVEAND SUITABLE TO TRANSMIT THE REST OF THE VISIBLE SPECTRUM SO THAT THEPROGRESS OF DEVELOPMENT OF SAID X-RAY-SENSITIVE LAYER CAN BE OBSERVED INROOMLIGHT.